Topic: Tornado Kills 9 in Japan

[Jeff Brislane]

just saw a news report of a killer tornado in Japan of all places but I have seen pretty violent tornadoes occur there before so I guess they are not new there, but I would say that the fatality rate of this tornado is certainly something new for them. I haven't found any images yet. Anyone else got any info?

Jeff.

[David C]

I didnt take note of where the tornado was, however Japan (Tokyo), always feels very soupy (muggy) through spring, summer and perhaps into fall -  no shortage of fuel that's for sure. Would be interesting to look at some charts and see what the situation was.

[David C]

AMS article - Tornadoes in Japan 
http://ams.allenpress.com/perlserv/?request=get-document&doi=10.1175%2F1520-0442(1997)010%3C1730:ASSOTA%3E2.0.CO%3B2

Just took a quick look at GFS for yesterday early afternoon (just for example) - very impressive and deep trough with negative tilt upper trough .......low topped supercells perhaps. GFS 500 temperature chart -- 100+knot midlevel jetstreak and similarly impressive low level flow.   

[Andrej Matko]

Here are two news links, third one is actual photo of the tornado, which appears to be shot relatively close to the circulation.

http://www.cnn.com/2006/WORLD/asiapcf/11/07/japan.tornado.ap/index.html
http://news.bbc.co.uk/1/hi/world/asia-pacific/6123426.stm
http://news.yahoo.com/photo/061107/ids_photos_wl/r2868142840.jpg

[Jimmy Deguara]

Wow Marko,

That tornado is might close to the personal space of the photographer!

Regards,

Jimmy Deguara

[Jeff Brislane]

On the evidence given by damage, eyewitnesses and the only actual photo of the twister, how can it not be a tornado? And the wind estimates of 70 meters per second are very strong and make it at least an F2. Now if there is rotation in the updraft as you suggest than it's a supercell spawned tornado but if theres no rotation in the updraft but merely rotation caused by wind convergence at the surface than it's a landspout. But an F2 landspout would be very rare.

John i'd think you'd have to ask "Is a supercell that's caused by local factors such as convergence and boundarys still a supercell?" or in fact is a supercell in it's simplest terms any storm that develops a rotating updraft no matter what the meso scale enviromental conditions are like?

[Jeff Brislane]

John, I did mention that the definition I gave of a supercell is in it's simplest terms. There are other factors that come into to play to decide whether a storm or not is in fact a supercell. Two other factors are of course the strength and duration of rotation as different people have different views on how these two factors relate to supercell definition.

And as you mentioned rotation within multi-cells, I would like to clarify that supercells embeded within multi-cells are in fact reasonably common. It would not be contentious at all to declare a supercell present within a multi-cell system and in the USA during the early season it's very common and they are no less supercells for being embeded.

Let me also say that short lived rotation in cells will very rarely create tornadoes. You need strong low level shear present to create even weaker tornadoes. If there is enough shear to create a weak tornadoe in a multi-cell updraft than the updraft would have to have strong enough rotation to declare it to be an embedded supercell. Landspouts though are a different story as they are not primarily meso-cyclone produced.

[Jeff Brislane]

John, are you testing me? When did I ever mention the word "isolated" in regard to embedded supercells? Isolated supercells occur just like that, isolated from other cells or meso-scale systems. I'm talking about embedded supercells which occur within meso-scale systems.
Posted on: November 14, 2006, 07:38:41 PMI think that maybe this topic has gone a little too far off course. Of relavance was the fact that a tornado of F2 intesity struck a small town in japan. This was more than likely a tornadic event given the desciptions by eyewitnesses and the level of destruction as well "cars lifted, power poles snapped, buildings collapsed, etc as opposed to a landspout event. Probable cause was a mini supercell (low topped supercell) in the system that produced the event. It would be similar to the tornado event from WA this august gone.

[Paul Graham]

Hi Everyone - Interesting discussion.  From what I understand of this event, it would seem to me that it was probably the result of a cold-air supercell, similar to the type that occur in southwest WA during the winter.  There was probably a bit more convective energy involved and the event turned out to be in the high-end of the intensity spectrum as far as cold-air events go.